Thread: How to wire Electric fans

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Hello there I just installed a dual fan set up on my mud drag pickup a 14 inch and 13 inch in one shroud. I have mounted it on my 4 core radiator and have it so it pulls. The fans are out of mercury v8 so I was told. Anyways I didn't use a relay or even a fuse when I wired it the first time. In a hurry. But I had the hot wire hooked to a toggle switch then into a constant power terminal in the fuse box with a conector. It worked for most of the race except in the end. I ended up melting the wire and conector by the fuse box. And the fans quit. The fans are hooked to each other and 3 wires come out of the harness on one side with a black, red, and a orange wire with a blue stipe. The only way we got the fans to go the right way was with the black and the orange-blue wire. Now I need some advice. On the correct way to wire this setup. I plan on wiring the fans seperate with a the hot wires going directly to the battery then maybe run the ground to the toggle switch. Will this work. Other wise I'm going to get a relay and some in-line fuses or breakers which I don't know how big of ones I need and hook them up. Any advice appreciated. Remember I want to turn the fans on manually so I can let it warm up a little bit before I run it wide open for 200 feet. New big block chevy in the pickup that I trying not to wreck. Goes like a raped ape. Thanks guys.

you HAVE to run a relay in the fan circuit, they draw a lot of amps and you risk setting the car on fire without having them properly wired. run one side of the switch to ground, and the other to the switch side of the relay. that way there is no power going through the switch, just a ground. Most automotive toggle switches arent made to handle high amperage draw.

I did the same thing on my ride ...I didnt know that a relay was needed & fried the wire from the ign switch & my toggle switcxh..
Live & learn.

Bob
67 Caliente